Red azo dye and process of making same.



UNIT 5 STATES Parana union.

TO CASSELLA COLOR COMPANY, OF NEW YORK, N. Y.

new Azo DYE AND FRQCESS OF MAKENGSAME.

Specification of Letters Patent.

Patented Feb. 20, 1906.

Application filed August 21, 1905. Serial No. 275,169.

To all whom zit-may concern: 6

Be it known that I, Gnono KALISCHER, doc tor of philosophy, a citizen of Prussia, and a resident of Frankfort-on-the-l\iain, in the Province of Hesse-Nassau and Kingdom of Prussia, Germany, have invented certain new and useful Improvements in Red Azo Dyes and Processes or" Making Same, of which the following is a specification.

My invention consists in combining in allraline solution one molecule of an aromatic diazo compoundwith .one molecule of the .5.oxynaphtho diamidobenzaldehydin. 7 .sul-

, fo-acid obtained by condensing in aqueous solution one molecule of'1.2 diamidona )htha lene.5.oxy.7.sulfo-acid with two molecules of mamidobenzaldehyde, (or m-nitrobenzaldehyde and subse uent reduction.) The azo dyes thus obtaine dye unmordanted cotton direct dyeing cotton azo' colors, these developed dyeings do not change to a deeper shade blue or to black, but turn a brighter red.

The fastness to washing thereby becomes excellent.

The method of production is illustrated by the followin example: 10.7 kilos 0-toluidin are vt rans iormed into the diazo com pound, which is introduced into the solution of forty-six kilos 5.0xynaphtho diamidobenzaldehydin.7.sulfo-acid in the pres ence of an excess of soda. The coloringmatter separates at once. It is easily soluble in water with a red color and dyes unmordented cotton direct a bluish-red shade. By diazotizing on the fiber and developing with beta-naphthol a bright scarlet is obtained. The dyestuff dissolves in concentrated sulfuric acid with a bluish-red color.

Having now described my invention and the manner in which it may be carried out, what I claim is 1. The process of preparing red azo dyes by combining in alkaline solution one molecule of an aromatic diazo compound with one molecule of the 5.0xynaphtho diamidobenzaldehydin. 7.su1fo-acid.

2. The coloring-matters obtainedbyconibining in alkaline solution one molecule of an aromatic diazo compound with one molecule of the 5.0xynaphtho diamidobenzaldehydin.7.sulfo-acid, the said coloring-matters being in the dry state red powders of a metallic luster, soluble in water with a yellowish-red to bluish-red color, dissolving in concentrated sulfuric acid with a bluish-red color, substantially as described.

Signed at Frankfort-on-the-Main, in the Province of Hesse-Nassau, Kingdom of Prussia, this 31st day of July,'A. D. 1905.

- GEORG KALISCHER.

Witnesses:

JEAN GRUND, CARI; GR'UND. 

